Dose-response relationships cancer slope factors

The key risk assessment parameter derived from the EPA carcinogen risk assessment is the cancer slope factor, which is a toxicity value that quantitatively defines the relationship between dose and response. The cancer slope factor is a plausible upper-bound estimate of the probability that an individual will develop cancer if exposed to a chemical for a lifetime of 70 years. The cancer slope factor is expressed as mg/kg/day. See Figure 9.33. 

Toxicity assessment includes characterization of the toxicity of a chemical, development of a dose-response relationship, and ultimately the development of exposure criteria. Toxicity values express a dose that is associated with either a given risk of cancer occurring over a lifetime of exposure (e.g., slope factors and unit risks) or a dose that is not expected to cause harm (e.g., RfDs). Some toxicity values are used as the basis for developing exposure criteria (RfDs) and some can be used as exposure criteria (e.g., RfCs). US EPA has developed toxicity values for many chemicals commonly associated with environmental contamination. Verified US EPA criteria are available in the Integrated Risk Information System (IRIS). 

---